Railway signaling system



April 25, 1939. P. H. DOWLING 2,155,532

RAILWAY SIGNALING" SYSTEM Original Filed April 22, 1931 l ENTOR Hi3 ATTORNEY Patented Apr. 25, 1939 UNITED STATES PATENT OFFICE RAILWAY SIGNALING SYSTEM Original application April 22, 1931, Serial No. 532,028. Divided and this application July 14,

1938, Serial No. 219,243

14 Claims.

My invention relates to railway signaling systems, and has for an object the provision of novel and improved systems for the control of signals by relays having no moving parts. More specifically, the present invention is directed to systems involving relays of the magnetic amplifier type, that is, relays wherein the output is controlled by varying the reactance of the output winding or by varying the magnetic coupling between a primary winding and secondary or output Winding.

The present application is a division of my copending application, Serial No. 532,028, filed on April 22, 1931, for Railway signaling systems.

I will describe one form of a system embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of signaling system embodying my invention.

Referring to the drawing, the reference char acters l and I designate the rails of a railway track along which traflic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 2 to form a series of track sections, of which only one complete section BC is shown in the drawing.

The rails ll are supplied with periodically interrupted unidirectional current of normal or reverse relative polarity, according as the section in advance of location is unoccupied or occupied. The manner in which this periodically interrupted current is supplied to the rails and its polarity controlled will become apparent as the description progresses.

The apparatus at each signal location such as B involves two magnetic amplifiers D and D and these amplifiers are of the inherently polarized or regenerative type. Amplifiers of this type are disclosed and claimed in Letters Patent of the United States No. 1,739,579, granted to me on December 17, 1929, for Electrical translating apparatus. When the lower rail I is positive, amplifier D responds and amplifier D does not, whereas when the upper rail I is positive, amplifier D will respond and amplifier D will not. Each of these amplifiers involves an input wind" ing 5, and an output winding 4 constantly supplied with alternating current from a source 22. The output circuit for amplifier D is connected with the input terminals of a full-wave rectifier l 9 and the output terminals of this rectifier are connected with the primary of a transformer 20 It follows that the output voltage of this transformer pulsates at twice the frequency of the track current, Transformer 2& is reactive, so that it will allow the pulsating or coded current to pass, but will prevent transmission of the high frequency alternating component of the output of rectifier IB in the event of a short circuit in the output winding 4 of amplifier D The secondary winding of transformer 20 is connected with the input terminals of a rectifier 2 I and the output terminals of this rectifier are connected with the input winding 26 of an amplifying transformer N This transformer includes a primary winding 21 constantly supplied with alternating current from a source 22 and a secondary winding 28. The transformer N preferably is of what is known as the discontinuous slow-acting type, disclosed in my copending application, Serial No. 463,020, filed June 23, 1930, now Patent No. 1,862,212 granted June 7, 1932, for Electrical translating apparatus. When this transformer is effectively energized, it supplies uninterrupted alternating current to the input terminals of a rectifier 23 through a condenser 29 and the output terminals of this rectifier are connected with the input winding of a balanced flux amplifying transformer P which .25 may for example be of the type disclosed in my copending application, Serial No. 438,916, filed March 25, 1930, now Patent No. 1,891,044 granted December 13, 1932, for Electrical translating apparatus. The primary winding of transformer 30 P is supplied with alternating current from a source 22, and the secondary winding is connected with the proceed lamp G. This secondary winding is also connected through a rectifier 24 with the input winding of an amplifying transformer l Q similar to transformer P and also with the input winding of a back contact amplifying transformer V. One characteristic of a back contact amplifying transformer is that a comparatively large current will flow in its output winding when the input winding is deenergized, but the current flowing in the output winding will be materially decreased when the reactance of the output winding is changed due to the energization of the input winding. Several types of magnetic amplifiers which operate in this manner are disclosed and claimed in an application for Letters Patent of the United States, filed by me on June 23, 1930, Serial No. 463,019, now Patent No. 1,835,209 granted December 8, 1931, for Electrical translating apparatus.

The apparatus interposed between amplifier D and the caution lamp Y is the same as that interposed between amplifier D and the proceed 55 lamp G. The secondary winding of transformer P is also connected with the input windings of both transformers Q and V, so that these transformers are effectively energized when either lamp- G or Y is lighted.

When transformer V is deenergized, the stop lamp R will be lighted, and this, of course, occurs only when both the proceed lamp G and the caution lamp Y are extinguished, that is, when the section BC immediately to the right of location B is occupied by a train.

When the section BC is occupied, both of the transformers Q and V will have their control windings deenergized because neither a transformer P nor P will be energized and so will not transmit the required energization to these windings. Since amplifying transformer Q is of the usual or front contact type, it will of course not deliver the required energy from its output winding when its control winding is deenergized, as above. Amplifying transformer V, however, is of the back contact type and so will deliver the required output when its control winding is deenergized.

When transformers Q and V are deenergized, therefore, transformer V is effective to supply current to a rectifier 25 and thence to the input winding of a front contact amplifying transformer Z, similar to transformers P and Q, which accordingly becomes energized and supplies current to the rails of the rear section. When transformers Q and V are both energized, (either transformer P or P energized) which will occur when either the section BC or both this section and the one immediately in advance thereof are unoccupied, the supply of current from transformer V is suppressed since this transformer is of the back contact type, and transformer Q is then effective to supply current through a rectifier 25 to the rails of the section immediately in the rear of location B. This current is of such polarity that the lower rail l is positive. When transformer Z is energized, as described above, its output winding supplies current to the rails of the rear section through a rectifier ZB and this current is of reverse polarity so that the upper rail I is positive. Two lamps 51 each having a positive temperature coeificient are connected across the output windings of rectifiers 25 and MW, respectively, for the purpose which is set forth in an application for Letters Patent of the United States, filed by me on April 1, 1931, Serial No. 526,797, now Patent No. 1,852,704 granted April 5, 1932 for Electrical apparatus. As explained in said patent, the purpose of these lamps is to render the output circuits of rectifiers 25Q and 26Q more efficient in that when rectifier ZBQ is supplying current, its lamp 5'! has a high resistance and so does not draw much load current, while the remaining lamp has a low resistance in order not to introduce too much resistance in series with the track circuit load. When, however, rectifier 25Q is feeding current, the reverse is true and its lamp then has a high resistance whereas the lamp associated with rectifier 26Q has a low resistance which, of course, is the more efficient arrangement under the latter operating condition.

The primary windings of amplifying transformers Q and Z are furnished with alternating current from a source 58, through a periodically operated contact 59, so that the current which is supplied to the rails of the rear section is periodically interrupted unidirectional current.

The apparatus which supplies current to the rails of the section immediately to the right of location B is similar in all respects to the corresponding apparatus, just described, which supplies current to the rails of the rear section.

The operation of the apparatus as a whole will be apparent from the foregoing description without further detailed explanation.

Although I have herein shown and described only one form of a signaling system embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a first and a second section of railway track, means for supplying current to the rails of said first section, a first magnetizable device having a control winding which receives energy from the rails of said first section and having an impedance winding linked magnetically with said control winding by means of a common magnetizable core, a second magnetizable device, means including a source of periodically varied current and said impedance winding for energizing said second magnetizable device, and means governed by said second magnetizable device for supplying rail current to said second section.

2. In combination, a first and a second section of railway track, means for supplying current to the rails of said first section, a first translating device having an input winding receiving energy from said rails and having an output winding, said input winding acting to vary the impedance of said output winding, a second translating device, means governed in accordance with the impedance of said output winding for energizing the input winding of said second translating device, and means including the output winding of said second translating device for supplying current to the rails of said second section.

3. In combination, a section of railway track, means for supplying unidirectional current impulses to the rails of said section, a magnetic amplifier comprising a magnetizable core having an input and an output winding thereon, means for transmitting said unidirectional current impulses from the rails of said section to said input winding for changing the permeability of said core in step with said impulses, a transformer, means including a source of current and the output winding of said magnetic amplifier for energizing said transformer, and traffic controlling apparatus governed by the output of said transformer.

4. In combination, a section of railway track, means for supplying unidirectional current impulses to the rails of said section, a magnetic amplifier comprising a magnetizable core having an input and an output winding linked magnetically thereon, means for establishing a flux in said core, means for transmitting said unidirectional current impulses from the rails of said section to said input winding for changing the flux in said core to thereby change the output of said output winding in step with said impulses, an. amplifying transformer controlled by said output winding, and traflic controlling apparatus governed by said amplifying transformer.

5. In combination, a section of railway track, means for supplying unidirectional current impulses to the rails of said section, a translating device all of the component parts of which are stationary, said device having a magnetizable core provided with an input and an output winding thereon,' means for transmitting said unidirectional current impulses from the rails of said section to said input winding for varying the fiux in said core in step with said impulses, an amplifying transformer, means including a source of current and the output winding of said translating device for energizing said transformer, and a signal governed by the output of said transformer.

6. In combination, a section of railway track, means for supplying the rails of said section with periodically varied current of normal or reverse polarity, two magnetic amplifiers each having an input circuit receiving energy from the rails of said section, an output circuit for each amplifier including a source of periodic current, the parts being so connected that one amplifier responds only to current of normal polarity and the other amplifier responds only to current of reverse polarity, traific controlling apparatus governed by said output circuits, and means interposed between said output circuits and said trafiic controlling apparatus to prevent said apparatus from responding to the periodic variations of the track rail current.

7. In combination, a section of railway track, means for supplying the rails of said section with periodically varied current, a magnetic amplifier having an input circuit receiving energy from the rails of said section, an output circuit for said amplifier including a source of periodic current, traflic controlling apparatus governed by said output circuit, and means interposed between said output circuit and said traflic controlling apparatus to prevent said apparatus from responding to the periodic variations of the track rail current.

8. In combination, a section of railway track, means for supplying the rails of said section with current of normal or reverse polarity, two magnetic amplifiers each having an input circuit receiving energy from the rails of said section, an output circuit for each magnetic amplifier including a source of periodic current, an amplifying transformer for each of said magnetic amplifiers controlled by the respective output circuit thereof, and trafiic governing apparatus selectively controlled by said amplifying transformers in accordance with the polarity of the current supplied to said section.

9. In combination, a first and a second section of railway track, means for supplying the rails of said first section with current of normal or reverse polarity, two static translating devices each having an input circuit receiving energy from the rails of said first section and selectively responsive in accordance with the polarity of the energy received thereby, traffic controlling apparatus for said first section selectively controlled by the output circuits of said translating devices, and means for supplying current to the rails of said second section controlled by the output circuits of said translating devices.

10. In combination, a section of railway track, means for supplying current to the rails of said section, a static translating device having an input circuit receiving energy from the rails of said section, an output circuit for said translating device including a source of current, a static back contact amplifier having an input circuit controlled by the output circuit of said translating device, and traffic governing apparatus controlled by the output circuit of said back contact amplifier.

11. In combination, a first and a second section of railway track, means for supplying current to the rails of said first section, a static translating device having an input circuit and an output circuit, means governed by energy received from the rails of said first section for controlling said input circuit, a static back contact amplifier, means including said output circuit and a source of current for controlling the input circuit of said back contact amplifier, and means controlled by the output circuit of said back contact amplifier for supplying current to the rails of said second section.

12. In combination, a first and a. second section of railway track, means for supplying current to the rails of said first section, a static translating device having an input circuit receiving energy from the rails of said first section, an output circuit for said translating device including a source of current, trafilc controlling means for said first section governed by said output circuit, and means also governed by said output circuit for supplying current to the rails of said second section.

13. In combination, a section of railway track, means for supplying current to the rails of said section, a static translating device having an input circuit receiving energy from the rails of said section, an output circuit for said translating device including a source of current, a static back contact amplifier and a static front contact amplifier both having an input circuit controlled by the output circuit of said translating device, and traffic controlling apparatus governed by the output circuit of said back contact amplifier and the output circuit of said front contact amplifier.

14. In combination, a section of railway track, means for supplying the rails of said section with periodically interrupted current of normal or reverse polarity, two regenerative magnetic amplifiers each having its input winding connected with the rails of said section, a circuit for the output winding of each amplifier including a source of alternating current, the parts being so connected that one amplifier responds to current of normal polarity but not to current of reverse polarity and that the other amplifier responds to current of reverse polarity but not to current of normal polarity, signals controlled by said output circuits, and slow acting devices interposed between said output circuits and said signals to prevent the signals from responding to the periodic interruption of the track rail current.

PHILIP H. ownmo. 

